Some engines are powered by more than just one fuel, for example, a combination of natural gas and diesel fuel may be used to power such dual fuel engines. The use of natural gas may allow significant saving in fuel costs while also maintaining diesel engine performance levels. In these dual fuel engines, the diesel fuel may act as an igniter for the natural gas inside a combustion chamber of a cylinder of the engine. These engines initially operate using diesel fuel and as temperature of inlet air rises, the natural gas is injected into the cylinder. As the natural gas is injected, the amount of the diesel fuel being consumed is reduced.
The natural gas is generally stored in a tank in a partially liquid and gaseous form. The natural gas is stored in the tank at a very low temperature. Accordingly, some heating means is associated with the tank, in order to increase the temperature of the natural gas before introduction into an intake manifold of the engine. In one example, engine coolant may be used to heat the natural gas. However, the coolant may have a relatively higher temperature due to heat exchange with components of the engine. In some examples, the temperature of the coolant may be approximately as high as 95° C. Accordingly, during the heat exchange with the coolant, the natural gas may also become very heated. Sometimes, uncontrolled increase in the temperature of the natural gas may affect the overall working of the engine. In some examples, the heated natural gas may heat up a gas shut-off valve associated the engine.
U.S. Published Application Number 2008/0276627 describes a fuel gas supply system. The fuel gas supply system is associated with a ship and is provided for supplying fuel gas to a high-pressure gas injection engine of the ship, wherein the ship has an LNG fuel tank for storing LNG as fuel and LNG is extracted from an LNG fuel tank of the ship, compressed at a high pressure, gasified, and then supplied to the high-pressure gas injection engine.